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11.6. Configuring ERPS
Overview
Function Introduction
ERPS technology increases the availability and robustness of Ethernet rings. In the event that a fiber cut occurs, ERPS converges in less than one second, often in less than 50 milliseconds.
The main idea is described as the following. ERPS operates by declaring an ERPS domain on a single ring. On that ring domain, one switch, or node, is designated the master node, while all other nodes are designated as transit nodes. One port of the master node is designated as the master node’s primary port to the ring; another port is designated as the master node’s secondary port to the ring. In normal operation, the master node blocks the secondary port for all non-ERPS traffic belonging to this ERPS domain, thereby avoiding a loop in the ring. Keep-alive messages are sent by the master node in a pre-set time interval. Transit nodes in the ring domain will forward the ERPS messages. Once a link failure event occurs, the master node will detect this either by receiving the link-down message sent by the node adjacent to the failed link or by the timeout of the keep-alive message. After link failure is detected, master node will open the secondary port for data traffic to re-route the traffic.
Principle Description
Reference: RFC 3619
Configuration
ERPS is a soft-state protocol. The main requirement is to enable ERPS on desired devices, and configure the ERPS information correctly for various network topologies.
This section provides ERPS configuration examples for their typical network topologies.
Configuring ERPS for a Single-Ring Topology
Configure same ERPS domain and ring at Switch1, Switch2 and Switch3. Switch1 is configured as ERPS master node and other two switches are configured as ERPS transit nodes. Interface agg11, which has two members called eth-0-9 and eth-0-10, is configured as primary interface at Switch1 and eth-0-13 is configured as secondary interface.
The ports accessing an ERPS ring must be configured as trunk ports, permitting the traffic of data VLANs to pass through. If the switch is enabled stacking, the port of ERPS ring should not on slave stacking device.
The ports accessing an ERPS ring must be configured as the members of the control VLAN, allowing the ERPS packets to be sent and received.
STP on ports accessing ERPS rings must be disabled.
Only one node can be configured as master node.
Control VLAN must not be configured as Layer 3 interface.
VLAN mapping must not be enabled on the ERPS ports.
Native VLAN of a port accessing an ERPS ring must not be set as the primary control VLAN or the secondary control VLAN.
The following configuration should be operated on all switches if the switch ID is not specified.
step 1 Enter the configure mode
Switch# configure terminal
step 2 Enter the vlan configure mode and create the vlan
Switch(config)# vlan database
Switch(config-vlan)# vlan 15
Switch(config-vlan)# exit
step 3 Enter the interface configure mode and set the attributes of the interface
As the topology shows eth-0-9 and eth-0-10 of Switch1 and Switch2 join agg 11 and connect to each other directly. eth-0-13 of Switch1 and Switch3 connect to each other directly. eth-0-17 of Switch2 and Switch3 connect to each other directly.
Interface agg 11 configuration for Switch1 and Switch2:
Switch(config)# interface eth-0-9
Switch(config-if)# no shutdown
Switch(config-if)# switchport mode trunk
Switch(config-if)# switchport trunk allowed vlan add 15
Switch(config-if)# static-channel-group 11
Switch(config-if)# exit
Switch(config)# interface eth-0-10
Switch(config-if)# no shutdown
Switch(config-if)# switchport mode trunk
Switch(config-if)# switchport trunk allowed vlan add 15
Switch(config-if)# static-channel-group 11
Switch(config-if)# exit
Switch(config)# interface agg11
Switch(config-if)# spanning-tree port disable
Interface eth-0-13 configuration for Switch1 and Switch3:
Switch(config)# interface eth-0-13
Switch(config-if)# no shutdown
Switch(config-if)# switchport mode trunk
Switch(config-if)# switchport trunk allowed vlan add 15
Switch(config-if)# spanning-tree port disable
Switch(config-if)# exit
Interface eth-0-17 configuration for Switch2 and Switch3:
Switch(config)# interface eth-0-17
Switch(config-if)# no shutdown
Switch(config-if)# switchport mode trunk
Switch(config-if)# switchport trunk allowed vlan add 15
Switch(config-if)# spanning-tree port disable
Switch(config-vlan)# exit
step 4 Create and enable ERPS domain.
ERPS domain for Switch1:
Switch(config)# erps 11
Switch(config)# erps 11 primary control vlan 15
Switch(config)# erps 11 mstp instance 0
Switch(config)# erps 11 ring 1 level primary
Switch(config)# erps 11 ring 1 mode master
Switch(config)# erps 11 ring 1 primary interface agg11
Switch(config)# erps 11 ring 1 secondary interface eth-0-13
Switch(config)# erps 11 ring 1 enable
Switch(config)# erps 11 enable
ERPS domain for Switch2:
Switch(config)# erps 11
Switch(config)# erps 11 primary control vlan 15
Switch(config)# erps 11 mstp instance 0
Switch(config)# erps 11 ring 1 level primary
Switch(config)# erps 11 ring 1 mode transit
Switch(config)# erps 11 ring 1 primary interface agg11
Switch(config)# erps 11 ring 1 secondary interface eth-0-17
Switch(config)# erps 11 ring 1 enable
Switch(config)# erps 11 enable
ERPS domain for Switch3:
Switch(config)# erps 11
Switch(config)# erps 11 primary control vlan 15
Switch(config)# erps 11 mstp instance 0
Switch(config)# erps 11 ring 1 level primary
Switch(config)# erps 11 ring 1 mode transit
Switch(config)# erps 11 ring 1 primary interface eth-0-17
Switch(config)# erps 11 ring 1 secondary interface eth-0-13
Switch(config)# erps 11 ring 1 enable
Switch(config)# erps 11 enable
step 5 Exit the configure mode
Switch(config)# end
step 6 Validation
Display the result on Switch1.
Switch# show erps 11
ERPS domain ID: 11
ERPS domain name: ERPS0011
ERPS domain mode: normal
ERPS domain primary control VLAN ID: 15
ERPS domain sub control VLAN ID: 0
ERPS domain hello timer interval: 1 second(s)
ERPS domain fail timer interval: 3 second(s)
ERPS domain protected mstp instance: 0
ERPS ring ID: 1
ERPS ring level: primary
ERPS ring 1 node mode: master
ERPS ring 1 node state: complete
ERPS ring 1 primary interface name: agg11 state:unblock
ERPS ring 1 secondary interface name: eth-0-13 state:block
ERPS ring 1 stats:
Sent:
total packets:51
hello packets:47 ring-up-flush-fdb packets:2
ring-down-flush-fdb packets:2 link-down packets:0
edge-hello packets:0 major-fault packets:0
Received:
total packets:21
hello packets:21 ring-up-flush-fdb packets:0
ring-down-flush-fdb packets:0 link-down packets:0
edge-hello packets:0 major-fault packets:0
Display the result on Switch2.
Switch# show erps 11
ERPS domain ID: 11
ERPS domain name: ERPS0011
ERPS domain mode: normal
ERPS domain primary control VLAN ID: 15
ERPS domain sub control VLAN ID: 0
ERPS domain hello timer interval: 1 second(s)
ERPS domain fail timer interval: 3 second(s)
ERPS domain protected mstp instance: 0
ERPS ring ID: 1
ERPS ring level: primary
ERPS ring 1 node mode: transit
ERPS ring 1 node state: link up
ERPS ring 1 primary interface name: agg11 state:unblock
ERPS ring 1 secondary interface name: eth-0-17 state:unblock
ERPS ring 1 stats:
Sent:
total packets:0
hello packets:0 ring-up-flush-fdb packets:0
ring-down-flush-fdb packets:0 link-down packets:0
edge-hello packets:0 major-fault packets:0
Received:
total packets:114
hello packets:113 ring-up-flush-fdb packets:1
ring-down-flush-fdb packets:0 link-down packets:0
edge-hello packets:0 major-fault packets:0
Display the result on Switch3.
Switch# show erps 11
ERPS domain ID: 11
ERPS domain name: ERPS0011
ERPS domain mode: normal
ERPS domain primary control VLAN ID: 15
ERPS domain sub control VLAN ID: 0
ERPS domain hello timer interval: 1 second(s)
ERPS domain fail timer interval: 3 second(s)
ERPS domain protected mstp instance: 0
ERPS ring ID: 1
ERPS ring level: primary
ERPS ring 1 node mode: transit
ERPS ring 1 node state: link up
ERPS ring 1 primary interface name: eth-0-17 state:unblock
ERPS ring 1 secondary interface name: eth-0-13 state:unblock
ERPS ring 1 stats:
Sent:
total packets:0
hello packets:0 ring-up-flush-fdb packets:0
ring-down-flush-fdb packets:0 link-down packets:0
edge-hello packets:0 major-fault packets:0
Received:
total packets:130
hello packets:129 ring-up-flush-fdb packets:1
ring-down-flush-fdb packets:0 link-down packets:0
edge-hello packets:0 major-fault packets:0
Configuring a Intersecting-Ring Topology
Configure same ERPS domain at Switch1, Switch2, Switch3 and Switch4. Switch1, Switch2 and Switch3 consist of ERPS primary ring 1 while Switch2, Switch3 and Switch4 consist of ERPS sub ring 2. Switch1 is configured as ERPS ring 1 master node and other two switches are configured as ERPS transit nodes while Switch4 is configured as ERPS ring 2 master node. In addition Switch2 is configured as edge node and Switch3 is configured as assistant-edge node.
The ports accessing an ERPS ring must be configured as trunk ports, permitting the traffic of data VLANs to pass through.
step 1 Enter the configure mode
Switch# configure terminal
step 2 Enter the vlan configure mode and create the vlan
Switch(config)# vlan database
Switch(config-vlan)# vlan 11,12
Switch(config-vlan)# exit
step 3 Enter the interface configure mode and set the attributes of the interface
Switch(config)# interface eth-0-9
Switch(config-if)# no shutdown
Switch(config-if)# switchport mode trunk
Switch(config-if)# switchport trunk allowed vlan add 11,12
Switch(config-if)# spanning-tree port disable
Switch(config-if)# exit
Switch(config)# interface eth-0-13
Switch(config-if)# no shutdown
Switch(config-if)# switchport mode trunk
Switch(config-if)# switchport trunk allowed vlan add 11,12
Switch(config-if)# spanning-tree port disable
Switch(config-if)# exit
Interface eth-0-20 configuration for Switch2 and Switch3:
Switch(config)# interface eth-0-20
Switch(config-if)# no shutdown
Switch(config-if)# switchport mode trunk
Switch(config-if)# switchport trunk allowed vlan add 11,12
Switch(config-if)# spanning-tree port disable
Switch(config-if)# exit
step 4 Create and enable ERPS domain.
ERPS domain for Switch1:
Switch(config)# erps 1
Switch(config)# erps 1 primary control vlan 11
Switch(config)# erps 1 sub control vlan 12
Switch(config)# erps 1 mstp instance 0
Switch(config)# erps 1 ring 1 level primary
Switch(config)# erps 1 ring 1 mode master
Switch(config)# erps 1 ring 1 primary interface eth-0-9
Switch(config)# erps 1 ring 1 secondary interface eth-0-13
Switch(config)# erps 1 ring 1 enable
Switch(config)# erps 1 enable
ERPS domain for Switch2:
Switch(config)# erps 1
Switch(config)# erps 1 primary control vlan 11
Switch(config)# erps 1 sub control vlan 12
Switch(config)# erps 1 mstp instance 0
Switch(config)# erps 1 ring 1 level primary
Switch(config)# erps 1 ring 1 mode transit
Switch(config)# erps 1 ring 1 primary interface eth-0-9
Switch(config)# erps 1 ring 1 secondary interface eth-0-20
Switch(config)# erps 1 ring 1 enable
Switch(config)# erps 1 ring 2 level sub
Switch(config)# erps 1 ring 2 edge-mode edge
Switch(config)# erps 1 ring 2 edge interface eth-0-13
Switch(config)# erps 1 ring 2 common interface eth-0-20
Switch(config)# erps 1 ring 2 srpt disable
Switch(config)# erps 1 ring 2 enable
Switch(config)# erps 1 enable
ERPS domain for Switch3:
Switch(config)# erps 1
Switch(config)# erps 1 primary control vlan 11
Switch(config)# erps 1 sub control vlan 12
Switch(config)# erps 1 mstp instance 0
Switch(config)# erps 1 ring 1 level primary
Switch(config)# erps 1 ring 1 mode transit
Switch(config)# erps 1 ring 1 primary interface eth-0-13
Switch(config)# erps 1 ring 1 secondary interface eth-0-20
Switch(config)# erps 1 ring 1 enable
Switch(config)# erps 1 ring 2 level sub
Switch(config)# erps 1 ring 2 edge-mode assistant-edge
Switch(config)# erps 1 ring 2 edge interface eth-0-9
Switch(config)# erps 1 ring 2 common interface eth-0-20
Switch(config)# erps 1 ring 2 enable
Switch(config)# erps 1 enable
ERPS domain for Switch4:
Switch(config)# erps 1
Switch(config)# erps 1 sub control vlan 12
Switch(config)# erps 1 mstp instance 0
Switch(config)# erps 1 ring 2 level sub
Switch(config)# erps 1 ring 2 mode master
Switch(config)# erps 1 ring 2 primary interface eth-0-9
Switch(config)# erps 1 ring 2 secondary interface eth-0-13
Switch(config)# erps 1 ring 2 enable
Switch(config)# erps 1 enable
step 5 Exit the configure mode
Switch(config)# end
step 6 Validation
Display the result on Switch1.
Switch# show erps 1
ERPS domain ID: 1
ERPS domain name: ERPS001
ERPS domain mode: normal
ERPS domain primary control VLAN ID: 11
ERPS domain sub control VLAN ID: 12
ERPS domain hello timer interval: 1 second(s)
ERPS domain fail timer interval: 3 second(s)
ERPS domain protected mstp instance: 0
ERPS ring ID: 1
ERPS ring level: primary
ERPS ring 1 node mode: master
ERPS ring 1 node state: complete
ERPS ring 1 primary interface name: eth-0-9 state:unblock
ERPS ring 1 secondary interface name: eth-0-13 state:block
ERPS ring 1 stats:
Sent:
total packets:1310
hello packets:1303 ring-up-flush-fdb packets:3
ring-down-flush-fdb packets:4 link-down packets:0
edge-hello packets:0 major-fault packets:0
Received:
total packets:921
hello packets:921 ring-up-flush-fdb packets:0
ring-down-flush-fdb packets:0 link-down packets:0
edge-hello packets:0 major-fault packets:0
Display the result on Switch2.
Switch# show erps 1
ERPS domain ID: 1
ERPS domain name: ERPS001
ERPS domain mode: normal
ERPS domain primary control VLAN ID: 11
ERPS domain sub control VLAN ID: 12
ERPS domain hello timer interval: 1 second(s)
ERPS domain fail timer interval: 3 second(s)
ERPS domain protected mstp instance: 0
ERPS ring ID: 1
ERPS ring level: primary
ERPS ring 1 node mode: transit
ERPS ring 1 node state: link up
ERPS ring 1 primary interface name: eth-0-9 state:unblock
ERPS ring 1 secondary interface name: eth-0-20 state:unblock
ERPS ring 1 stats:
Sent:
total packets:0
hello packets:0 ring-up-flush-fdb packets:0
ring-down-flush-fdb packets:0 link-down packets:0
edge-hello packets:0 major-fault packets:0
Received:
total packets:988
hello packets:985 ring-up-flush-fdb packets:2
ring-down-flush-fdb packets:1 link-down packets:0
edge-hello packets:0 major-fault packets:0
ERPS ring ID: 2
ERPS ring level: sub
ERPS ring 2 node mode: transit
ERPS ring 2 edge node mode: edge
ERPS ring 2 node state: link up
ERPS ring 2 edge interface name: eth-0-13 state: unblock
ERPS ring 2 common interface name: eth-0-20 state: unblock
EPRS ring 2 SRPT is disabled
ERPS ring 2 stats:
Sent:
total packets:0
hello packets:0 ring-up-flush-fdb packets:0
ring-down-flush-fdb packets:0 link-down packets:0
edge-hello packets:0 major-fault packets:0
Received:
total packets:858
hello packets:856 ring-up-flush-fdb packets:1
ring-down-flush-fdb packets:1 link-down packets:0
edge-hello packets:0 major-fault packets:0
Display the result on Switch3.
Switch# show erps 1
ERPS domain ID: 1
ERPS domain name: ERPS001
ERPS domain mode: normal
ERPS domain primary control VLAN ID: 11
ERPS domain sub control VLAN ID: 12
ERPS domain hello timer interval: 1 second(s)
ERPS domain fail timer interval: 3 second(s)
ERPS domain protected mstp instance: 0
ERPS ring ID: 1
ERPS ring level: primary
ERPS ring 1 node mode: transit
ERPS ring 1 node state: link up
ERPS ring 1 primary interface name: eth-0-13 state:unblock
ERPS ring 1 secondary interface name: eth-0-20 state:unblock
ERPS ring 1 stats:
Sent:
total packets:0
hello packets:0 ring-up-flush-fdb packets:0
ring-down-flush-fdb packets:0 link-down packets:0
edge-hello packets:0 major-fault packets:0
Received:
total packets:645
hello packets:644 ring-up-flush-fdb packets:1
ring-down-flush-fdb packets:0 link-down packets:0
edge-hello packets:0 major-fault packets:0
ERPS ring ID: 2
ERPS ring level: sub
ERPS ring 2 node mode: transit
ERPS ring 2 edge node mode: assistant edge
ERPS ring 2 node state: link up
ERPS ring 2 edge interface name: eth-0-9 state: unblock
ERPS ring 2 common interface name: eth-0-20 state: unblock
ERPS ring 2 stats:
Sent:
total packets:0
hello packets:0 ring-up-flush-fdb packets:0
ring-down-flush-fdb packets:0 link-down packets:0
edge-hello packets:0 major-fault packets:0
Received:
total packets:645
hello packets:644 ring-up-flush-fdb packets:1
ring-down-flush-fdb packets:0 link-down packets:0
edge-hello packets:0 major-fault packets:0
Display the result on Switch4.
Switch# show erps 1
ERPS domain ID: 1
ERPS domain name: ERPS001
ERPS domain mode: normal
ERPS domain primary control VLAN ID: 0
ERPS domain sub control VLAN ID: 12
ERPS domain hello timer interval: 1 second(s)
ERPS domain fail timer interval: 3 second(s)
ERPS domain protected mstp instance: 0
ERPS ring ID: 2
ERPS ring level: sub
ERPS ring 2 node mode: master
ERPS ring 2 node state: complete
ERPS ring 2 primary interface name: eth-0-9 state:unblock
ERPS ring 2 secondary interface name: eth-0-13 state:block
ERPS ring 2 stats:
Sent:
total packets:814
hello packets:810 ring-up-flush-fdb packets:2
ring-down-flush-fdb packets:2 link-down packets:0
edge-hello packets:0 major-fault packets:0
Received:
total packets:774
hello packets:774 ring-up-flush-fdb packets:0
ring-down-flush-fdb packets:0 link-down packets:0
edge-hello packets:0 major-fault packets:0
Application cases
N/A